Improvement in steam-boilers



Unire STATES:

PATENT Orrrcn.

THOMAS MAIN, OF GREEN-POINT, NEV YORK.

IMPROVEMENT IN STEAM-soirees.

t Specification forming part of Lettersrfateut No. 47,368, dated May 30, 186i).

I o allzu/"1,0112, t mag/concern:

`Be it known that I, THOMAS MAIN, of Green Point, in the county of Kings and State of New York, have invented a new and useful Improvementin Steam-Boilers; Aand I do hereby declare that the following is a full, clear, and exact description thereof, which will enable those skilled in the art, to make and use the same, reference being had tothe accompanying drawings, forming part of this specification, in which- Figure lis an elevation of a vertical section of a steam-boiler made according to my invention. Fig. 2 is an elevation of the boiler' as seen from the outsidewFig. 3 is a transverse section on the line a' of Fig. l.

Similar letters of reference indicate like parts.

This invention consists of lcertain improvements in the construction of vertical steamboilers wherein a combustion-chamber is employed and the flues both downward and upward are made to pass through the water-space, and wherein the upper parts of the apparatus are so arranged that the products of combustion and heated gases are made to superheat the steam in the steam-space of the boiler.

A represents a vertical `boiler supported upon a suitable base7 E, which, in this example of my invention, incloses the ash-pit c of the furnace. The boiler here shown is cylindrical; but it may be of any suitable and convenient form.

B is the furnace, and b its grate. The walls of the furnace are increased in diameter at a line sufficiently high to be above the highest point at which the fuel will lie into a combustion-chamber, C, of any suitable form, and which is here made circular, like the furnace. The sides and top of this chamber are closed or solid, and its lower edge is separated from the upper edge of the wall of the iirechamber by an annular plate, I, which also helps to secure them in their places. The plate I is perforated to receive flue-tubes f, arranged vertically outside of the firechamber, their lower ends opening into an annular line-space, h, through an annular plate, J which extends from the outside of the fire-chamber to the shell c of the boiler. The bottom of the fluespace h is also the bottom of the boiler.

K is the upper plate proper of the boi1er,or what answers for its crown. It is secured in any proper manner tothe shell a, near its up peredge, and has a steam-dome or steamspace, d, rising from its center. The plate K is perforated'near its circumference to receive the upper ends of flue-tubes g, which are placed in several sets-four tubes in a set-about the entire circumference of the plate. Their lower ends pass through and are secured in the annular plate J, before mentioned, beingsitu; ated between the flue-tubes fand the shell c of the boiler. An upperfluespace, e, is made abovef the upper plate,K,`by means of a hood or roof, n, with inclined sides, as in this `enample, or it may be arched or of any other form, from the center of which rises a discharge flue or chimney, F. The `hood n ts over or is connected in any other suitable man ner to the upper edge of the shell a of the boiler. descend from the lower sides of the dome d to the top of the combustion-chamber C, to which they are properly secured.

In order to obtain access to the flue-tubes g, I construct doors j in the hoodn ofthe upper iiue space--one above each set of tubes-through which doors easy access can be had to the tubes in order to clean them of soot and other obstructions. I have shown only three such doors in this example of my invention; but they are to be made around the whole hood n over each set of the fine-tubes g.

A man-hole may be made in the shell a of the boiler at any suitable point above the level of the combustion-chamber C. I have not thought it` necessary to show one in this example, since its office and manner of construction are familiar to those persons who are skilled in the art to which this invention belongs; but I have indicated a proper position for such a man-hole by red outline in Fig. 2. It should be located in such a position as to open betweentwo adjacent series of due-tubes g.

The water-space in myboiler is indicated by the letter D, lthe steam-space lying above the water-line, as indicated by the letter D. The water is free to circulate around and between the flue-tubes f and g, between the shell a of the boiler and the walls of the nrc-chamber B and combustion-chamber C, and also over the The plate K is stayed by rods i, which top surface of the latter chamber. The radil to control the draft of the furnace. The course ating-surfaces ofthefurnace and its flues are thus surrounded by the Water-space, the bottom plate, J, of that space being ou a line below the level of the grate'of the furnace. The flues g pass through the steamspace also, which, as before explained7 is enlarged by thc addition of the dome d, which extends upward into thc upper nue-space, c. The products of combustion and gases from the furnace will have parted with the greater part of their heat when they have reached the chimney F, and the steam in the upper part, D d, of the boiler will be more or less superheated in the ordinary Working of the furnace by means of the radiation of heat from the flues f/ and the fluespace c, the upper parts of said iues g being surrounded by steam, while the steam in the dome d is surrounded by the upper flue-space7 By constructinga boiler in the way here explained I am able to dispense almost entirely with braces, which are in ordinary constructions considered indispensable. The doorway G of the furnace passes through the side and Walls of the boiler and nrc-chamber, and is surrounded above and below and on its two sides by the Water-space, the iiuesj' being of 'course omitted at the place of the doorway.

G is the furnace-door7 and H is the ash-pit door7 both made in any proper manner, so as of the products of combustion is through the mixing and combustion chamber C; thence down through the flues f into the flue-space h; thence up through the fiues g into the upper due-space, e, and thence into the chimney. The position of the nues f, as well as their direction and the restricted passage-Way furnished by their narrouT throats, cause the gases from the fire to be retained a short time in the chamber C, andthus gives time for the air to mix with them While they are at a high temperature, so that they will be thoroughly consumed before they escape down through the fines j'.

l claim as new and desire to secure by Letters Patent- The combination, in a vertical steam-boiler,

of the fire-chamber B, the enlarged combustion-chamber C, surmounting the said rechamber and surrounded by the Waterspace, the descending lines f, and ascending ues g, passing through the said water-space7 and the upper due-space, e, surrounding ,the steam dome d, all as herein described.

THOMAS MAIN.

fitnessesz M. M. LIVINGSTON, C. L. Tormrr. 

